February Letters 70

Science and Climate Change

I am writing to express my disappointment with Thomas Sieger Derr’s “Strange Science” (November 2004).While I agree with Professor Derr that the science on global warming is uncertain, the conclusions he draws from the data are irresponsible. Prof. Derr argues that America was right to opt out of the Kyoto protocol because it would have harmed the economy without improving the environment. While that position is defensible, Prof. Derr’s failure to say anything more is not. As Christians we are supposed to be stewards of the earth. Prof. Derr proposes no meaningful alternative to Kyoto and no vision of what a Christian environmentalism might mean. Prof. Derr seems to think that there is no reason to be alarmed about the volume of pollutants we are emitting, and he blames arrogant academics, the UN, and the media for exaggerating our environmental problems. Even if one accepts his arguments, I think it reasonable to say that the excesses of our consumerist society are harming us both spiritually and environmentally and that something about our lifestyles needs to change.

Brendan Wilson
Washington D.C.

Thomas Sieger Derr has pricked a festering blister within the academic and political communities. I suspect that the reaction will be harsh from those scientists whose reputations have been built upon doomsday predictions. The weight of the evidence, however, is entirely on the side of Professor Derr and his argument.

The “greenhouse effect” is a model for explaining climate change. Like all models, it makes testable predictions. One prediction is that the planet will warm in proportion to an increase in the concentration of carbon dioxide and water vapor in the atmosphere. As Prof. Derr observes, the evidence only superficially supports this prediction. He does not add, as he could have, that the margin of error involved in measuring temperature change is larger than the observed change, a fact that casts doubt upon the reality of any observed increase or decrease in temperature.

Another prediction of the greenhouse model is that temperature increases will be greatest at elevations closest to sea level and will diminish at higher elevations. This prediction is based upon the greater density of the atmosphere, as well as the higher concentration of carbon dioxide and water vapor, at lower elevations. But no such correlation has been observed.

Scarce public resources should be devoted to solving problems that the evidence suggests are real. The greenhouse effect does not seem to be one of those problems. Perhaps, as Prof. Derr suggests, the greenhouse theory lives on because of the threat honesty would pose to the reputations and fundraising power tied to it.

Benjamin F. Lasseter
Indianapolis, Indiana

As someone who works on understanding the earth’s ecosystem for a living, I am often put off by irresponsible claims about the effects of global warming. Nevertheless, it bothers me to see Thomas Sieger Derr repeat two persistent myths of the global warming skeptics’ camp, one of which is simply false, the other of which is self-refuting.

The first myth is that “there is not a very good correlation between atmospheric carbon dioxide and past climate changes.” This statement is true over the relatively recent period since the end of the last glaciation. Yet when viewed over a longer period, say the last 700,000 years, the correlation is actually extraordinarily good, as confirmed by ice core records taken by the Vostok Project and the European Project for Ice Coring in Antarctica (EPICA). Higher carbon dioxide levels are the leading hypothesis invoked to explain higher temperatures during the Cretaceous period, to resolve the “faint young sun” paradox (i.e., to explain why the earth did not freeze over in earlier times when the sun was not as bright), and to explain the emergence of the earth from global glaciation during the Neoproterozoic period. For many climate scientists, myself included, these correlations, rather than the output of climate models, represent the best calibration of the potential impact of global warming. The calibration that emerges, while not catastrophic, is significant.

Professor Derr’s second mistake is to claim that “the likeliest cause of climate trends seems to be solar variability.” The actual change in solar radiation associated with known variability is much smaller than the change in the atmosphere’s ability to trap radiation associated with carbon dioxide. Proponents of the solar variability hypothesis must come up with an amplifier for solar forcing that does not serve as an amplifier for greenhouse gas forcing. This they have failed to do. Thus, while certain models are able to attribute warming during the first part of the twentieth century to solar variability, those same models also predict a significant response to greenhouse gas forcing.

As a responsible scientist I am limited to what our best understanding, embodied in models of climate, actually shows. What it shows is global warming resulting from carbon dioxide emissions. While the hysterical rhetoric of many environmental groups is of little use, it is equally useless to refuse to admit that the best available science may have something to say about the relative merits of a given plan of action.

Anand Gnanadesikan
Plainsboro, New Jersey

Thomas Sieger Derr replies:

I thank Benjamin F. Lasseter for his support and for his additions to my argument.

Brendan Wilson wants me to say more, or perhaps to have written a different article. Actually, I have been for years a strong defender of environmental stewardship”from the perspective of Christian humanism. I certainly believe in restricting atmospheric pollutants”as indeed my article says, in so many words. So we ought not to have any disagreement there. But my essay was about something else.

There is, not surprisingly, considerable disagreement on the causes of the fluctuations in the earth’s temperature over centuries and millennia, and Anand Gnanadesikan’s letter reflects that. I have been more impressed than he is by papers that argue for a solar hypothesis. Such research argues that the geological record shows essentially no correlation between carbon dioxide levels and temperature change for the last half-billion years, even though those levels have at times been eighteen times higher than they are today. Changes in earth temperature correspond, instead, to solar and galactic movement. The question of whether or not this is true is fodder for future scientific discussion. But in any case Dr. Gnanadesikan’s letter does not affect my main point”namely, that variations in earth’s temperature are naturally occurring and do not correlate with human activity.

Transsexual Truths?

In “Surgical Sex” (November 2004) Paul McHugh is certainly right to assert that sexual identity (or, as I prefer, gender) is not subject to change; it is most certainly inherent. About nearly everything else, however, Dr. McHugh is quite wrong. To begin with, I honestly have to wonder how many transsexuals Dr. McHugh has encountered, either before or after surgery. While some do match his descriptions, most of those I know have actually been quite successful in their transformation and are indistinguishable from other women.

Contrary to Dr. McHugh’s claims, many transsexual women show considerable interest in children and many mourn the fact that they will never be able to bear a child. I myself have cried bitter tears over this. And yes, some transsexual women do identify as lesbian”just like women who are not transsexual. Likewise, many transsexual men identify as gay. Such is to be expected if transsexualism is more than just a choice.

The report published by Jon Meyer (and cited authoritatively by Dr. McHugh) was met with considerable skepticism at the time it was published. It was widely criticized for methodological flaws, while other studies have shown that Meyer’s study was incorrect in its conclusions. Nevertheless, it was used by Johns Hopkins as an excuse to shut down its gender identity clinic. I also note that Dr. McHugh mentions the Clarke Institute. The fact is that this agency has a notorious reputation for mistreating transsexual patients, forcing them to meet unreasonable standards, and denying them the hormones needed to modify their bodies.

One wonders why Dr. McHugh would choose such a cruel approach to the treatment of transsexuals. Sex- reassignment surgery has proven to be the only successful treatment for these patients, and yet for some reason he wishes to deny this. He makes a rather clumsy attempt to justify his position by comparing the treatment of adults who are transsexual with the treatment of children who are intersexed. Ironically, the arguments for one contradict the arguments for the other. Children who are intersexed have traditionally been surgically altered in whatever manner is simplest. This has often resulted in a child who has a male brain being given a female body. As Dr. McHugh points out, such a child is tormented by the attempt to force him to live at odds with his natural inclinations. And yet, he cannot find the compassion to provide treatment to those who, for whatever reason, were born male but whose brains were not sexualized as male in the womb. Even though both groups face the same set of problems, Dr. McHugh sets out to protect one group while effectively punishing the other.

Jennifer Usher
San Francisco, California

Correction

On the table-of-contents page of the January issue, the author of the poem printed on page 31 (“Bearing Up”) was incorrectly given as Oliver Thomas. The author’s name is in fact Oliver Murray. We regret the error.